JP2016025073A - Battery module and battery pack including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery module capable of detecting the operation of a current interrupt device mechanism without fault when the current interrupt device mechanism operates; and a battery pack including such a battery module.SOLUTION: A battery module 20 comprises: battery cells 30; an energization circuit provided in each battery cell 30; a current interrupt device mechanism provided in each battery cell 30, which cuts off the energization circuit on condition that an internal pressure of the battery cell is a set value or larger; a sound sensor 70 for detecting a sound; high-pass filter means for attenuating, of detection signals output by the sound sensor 70, components of frequencies under a preset set frequency, and outputting components of frequencies equal to or higher than the set frequency without attenuating them; and operation detecting means for detecting the operation of the current interrupt means based on detection signals output by the high-pass filter means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery module and a battery pack including the battery module.

  Rechargeable secondary batteries are widely used in various fields. Since the voltage obtained in a single secondary battery is small, if a high voltage is required, prepare multiple battery cells that are the smallest unit, and connect these multiple battery cells in series to form a battery module. do it. However, the variation in the battery capacity of each battery cell causes a reduction in the battery capacity of the entire battery. For this reason, the battery module in which the battery cells are connected in series may be provided with a monitoring ECU, and the monitoring ECU may perform voltage monitoring for each battery cell. Each control of discharge and charge is performed based on the monitoring result by the monitoring ECU, and suppression of deterioration of battery characteristics due to overdischarge or overcharge is achieved. However, even if voltage monitoring is performed by the monitoring ECU, there is a possibility that control based on the monitoring result is not appropriately performed for some reason. For this reason, a current interruption mechanism (CID: Current Interrupt Device) is often mounted on the battery cell.

  The charging control by monitoring the voltage of the monitoring ECU is normally performed so that the current interrupt mechanism does not operate. When the current interruption mechanism operates during the charge control, there is a possibility that the charge control cannot be performed properly for some reason. When the current interruption mechanism is activated, the connection of the energization path used for discharging from the battery module and charging to the battery module is disconnected. After the operation of the current interruption mechanism, the disconnection of the energization path by the current interruption mechanism may be automatically released due to, for example, a decrease in the internal pressure of the battery cell. In this case, the battery cell returns to a state in which current can flow (re-conduction state). For this reason, although the control based on the monitoring result is not properly performed, the charging or discharging control is performed again. In order to prevent such a reconducting state from being reached, it is important to reliably detect that the current interrupting mechanism has been activated.

  As a conventional technique related to the battery module, for example, a battery module disclosed in Patent Document 1 is known. The battery module disclosed in Patent Literature 1 includes a cell group including a plurality of batteries and an ECU. The safety valve of the battery faces the facing member. A sound sensor is disposed between the facing member and the cell group, and the sound sensor is connected to a valve operation detection unit of the ECU. The valve operation detection unit detects that the safety valve of at least one battery in the cell group has been operated based on the output signal of the sound sensor. As a result, the operation of the safety valves of the plurality of batteries is detected only by providing one or a small number of sound sensors for the plurality of batteries.

International Publication No. 2011/101942

  However, the conventional battery module has a problem that even if the current interruption mechanism is activated, it cannot be reliably detected that the current interruption mechanism is activated. Moreover, the battery module disclosed in Patent Document 1 is a technique for detecting the operation sound of the safety valve by a sound sensor, and there is a problem that the operation of the current interruption mechanism cannot be detected. In addition, when this type of battery module is mounted on a vehicle, it is difficult to distinguish between various noises generated during traveling and the operating sound of the safety valve. Furthermore, the operation pattern of the safety valve varies, and the operation sound varies depending on the operation pattern of the safety valve. For this reason, there is a possibility that the operation of the safety valve cannot be reliably detected.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery module capable of reliably detecting the operation of the current interrupt mechanism when the current interrupt mechanism operates, and the battery module. In providing battery packs.

  In order to solve the above problems, the present invention provides a plurality of battery cells, an energization path provided in the battery cell, the battery cell, and the battery cell having an internal pressure equal to or higher than a set value. In a battery module having a current interruption mechanism for interrupting an energization path, among the sound sensor for detecting sound and the detection signal output by the sound sensor, the frequency component less than a preset frequency is attenuated and the setting is made A high-pass filter unit that outputs a frequency component higher than the frequency without attenuation, and an operation detection unit that detects the operation of the current interrupt mechanism based on a detection signal output from the high-pass filter unit.

  According to the present invention, the sound sensor outputs a detection signal of the detected sound, and the high-pass filter circuit attenuates a frequency component less than a preset set frequency among the detection signals output from the sound sensor and the set frequency. The above frequency components are output without being attenuated. When the detection signal after the output of the high-pass filter means includes a frequency component that is equal to or higher than the set frequency, the operation detection means detects that the current interrupt mechanism is activated. That is, if the current interruption mechanism is activated, the operation of the current interruption mechanism can be reliably detected.

In the battery module, the operation detection unit may detect the operation of the current interrupting mechanism based on a comparison between a sound duration detected by the sound sensor and a preset set duration. Good.
In this case, the duration of the sound (operating sound) when the current interrupting mechanism is activated coincides with a preset set duration. For this reason, even if the detection signal after the output of the high-pass filter means includes a frequency component that is equal to or higher than the set frequency, if the duration of the sound is longer than the set duration, the operation detection means is activated by the current interruption mechanism. It is not detected that it was done. That is, it is not erroneously detected that the current interrupting mechanism is operating by a sound including the same frequency component as the operating sound of the current interrupting mechanism.

Further, in the battery module, the current interrupting mechanism includes a deforming plate that is instantaneously deformed by an internal pressure equal to or higher than a set value of the battery cell, and that interrupts the energization path by the deformation. It is good also as a structure which emits the operation sound containing the component more than the said setting frequency.
In this case, when the internal pressure of the battery cell reaches or exceeds the set value, the deformable plate is instantaneously deformed, and due to the deformation, an operation sound including a component of the set frequency or more is emitted. For this reason, it becomes easy to distinguish from the sound other than the operation sound of the current interruption mechanism, and it can be detected more reliably that the current interruption mechanism is activated.

In the battery module described above, the deformation plate may emit an operation sound having a duration that matches the set duration during deformation.
In this case, the operating sound when the deforming plate is deformed includes a component having a frequency equal to or higher than the set frequency, and the duration of the operating sound matches the set duration. For this reason, it becomes easy to distinguish more reliably from sounds other than the operating sound of an electric current interruption mechanism.

Moreover, it is good also as a battery pack which has said battery module and the case where the battery module is accommodated.
In this case, since the battery module is accommodated in the case, it is easy to cut off sound other than the operating sound of the current cut-off mechanism by the case.

  ADVANTAGE OF THE INVENTION According to this invention, if a current interruption mechanism act | operates, the battery module which can detect the action | operation of a current interruption mechanism reliably and a battery pack provided with the battery module can be provided.

It is a longitudinal cross-sectional view which shows the outline | summary of a battery pack provided with the battery module which concerns on embodiment of this invention. It is a perspective view of the battery module which concerns on embodiment of this invention. It is an AA arrow line view in FIG. It is the perspective view and exploded perspective view of the battery cell which concern on embodiment of this invention. It is a longitudinal cross-sectional view of the battery cell which concerns on embodiment of this invention. (A) is a longitudinal cross-sectional view of the current interruption mechanism in a non-operation state, (B) is a longitudinal cross-sectional view of the current interruption mechanism in an operation state. It is a block diagram which shows schematic structure of the battery module which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows the outline | summary of the battery pack which concerns on a modification.

  Hereinafter, a battery pack according to an embodiment of the present invention will be described with reference to the drawings. This embodiment explains the example applied to the battery pack for vehicle mounting. A battery pack 10 shown in FIG. 1 includes a case 11 and a plurality of battery modules 20 accommodated in the case 11. As shown in FIG. 1, the case 11 includes a case main body 17 having an opening 18 and a lid member 19 that covers the opening 18 and is fixed to the case main body 17. The case body 17 includes a rectangular plate-shaped bottom portion 12, rectangular plate-shaped side wall portions 13 to 15 and a top plate portion 16 that are provided upright from three sides of the bottom portion 12. The side wall 15 is erected from the long side opposite to the opening 18 side of the bottom 12. The side wall 13 is erected from one short side of the bottom 12, the side wall 14 is erected from the other short side of the bottom 12, and the side wall 13 and the side wall 14 are parallel to each other. The top plate portion 16 is connected to the upper sides of the side wall portions 13 to 15 and is parallel to the bottom portion 12. The opening 18 is formed by being surrounded by the bottom 12, the top plate 16, and the side walls 13, 14 in the case main body 17.

  In this embodiment, five battery modules 20 are accommodated in the case 11. The five battery modules 20 are accommodated in the case 11 by being divided into a first battery group G1 in which the three battery modules 20 are stacked and a second battery group G2 in which the two battery modules 20 are stacked. ing. The lowermost battery module 20 of the first battery group G1 and the lower battery module 20 of the second battery group G2 are disposed on the bottom 12 of the case 11.

  A space corresponding to one battery module 20 exists above the second battery group G2 in the case 11. In this space, a control ECU 21 and a junction box 22 are arranged. The control ECU 21 is disposed above the upper battery module 20 of the second battery group G2, and the control ECU 21 controls each battery module 20. As shown in FIG. 1, the control ECU 21 is fixed to the side wall portion 15. The control ECU 21 has a harness (not shown) provided toward the junction box 22 and a harness (not shown) connected to the battery module 20. The junction box 22 is provided with a relay, various wirings, a bus bar and the like (not shown).

  As shown in FIGS. 2 and 3, the battery module 20 includes a plurality of battery cells 30 arranged in parallel and a battery holder 23 that holds the plurality of battery cells 30 arranged in parallel. End plates 24 are provided at both ends of the battery module 20 in the juxtaposition direction of the battery cells 30. A bracket 25 is attached to the end plate 24. The battery module 20 is fixed to the side wall 15 of the case 11 by attaching the bracket 25 to the side wall 15 of the case 11 via a bolt (not shown). The battery holder 23 supports a mounting plate 26 that is disposed to face the battery cell 30. The mounting plate 26 is provided with a monitoring ECU 27 that controls each battery cell 30.

  Although not shown, the monitoring ECU 27 includes a central processing unit (CPU), a memory unit such as a RAM and a ROM, an input unit and an output unit, and is electrically connected to the control ECU 21 via a harness. The monitoring ECU 27 monitors the state of the battery module 20 such as the temperature of the battery cell 30 and the voltage between the battery cells 30. Monitoring information regarding the state of the battery module 20 detected by the monitoring ECU 27 is transmitted to the control ECU 21. The control ECU 21 controls the battery module 20 based on monitoring information regarding the state of the battery module 20 of the monitoring ECU 27.

  The battery cell 30 of this embodiment is a secondary battery such as a lithium ion secondary battery or a nickel hydride secondary battery, and is a square secondary battery. As shown in FIG. 4, an electrode assembly 40 is accommodated in the battery case 31 of the battery cell 30. The battery case 31 has a bottomed cylindrical case main body 32 and a rectangular flat plate-shaped lid 33 that closes the opening of the case main body 32. The case main body 32 and the lid body 33 are made of a metal material (for example, aluminum). As shown in FIG. 5, an insulating sheet 34 is attached to the inner surface of the case body 32 as an insulating member for insulation from the electrode assembly 40 housed in the battery case 31. Further, an insulating sheet 35 as an insulating member for insulating the electrode assembly 40 accommodated in the battery case 31 is attached to the inner side surface of the lid 33.

  As shown in FIG. 4, the lid 33 has a pair of through holes 36. A safety valve 37 is provided near the center of the lid 33 in the longitudinal direction. The safety valve 37 has a function of opening when the pressure in the battery case 31 reaches a predetermined pressure due to the generation of gas in the battery case 31 and releasing the gas in the battery case 31 to the outside. The lid 33 is provided with a liquid injection port 38 for injecting the electrolytic solution into the battery case 31, and the liquid injection port 38 is sealed with a sealing member 39.

  The electrode assembly 40 is a power generation element that generates a battery function (such as charging / discharging). As shown in FIG. 4, the electrode assembly 40 includes a sheet-like positive electrode 41 and a sheet-like negative electrode 42, and a sheet-like separator 43 interposed between the positive electrode 41 and the negative electrode 42. The separator 43 is formed of an insulating material that enables the electrolyte solution to flow. In the electrode assembly 40, the positive electrodes 41 and the negative electrodes 42 are alternately stacked via the separators 43. The electrode assembly 40 includes a positive electrode current collector 44 that is electrically connected to the plurality of positive electrodes 41, and a negative electrode current collector 45 that is electrically connected to the plurality of negative electrodes 42. The positive electrode current collector 44 is electrically connected to the positive electrode terminal 46. The negative electrode current collector 45 is electrically connected to the negative electrode terminal 47 through the current interruption mechanism 50.

  In a state where the electrode assembly 40 is accommodated in the battery case 31, the positive terminal 46 and the negative terminal 47 are exposed to the outside of the battery case 31 through the pair of through holes 36 of the lid 33. A cylindrical insulating ring 48 made of resin for insulating the positive electrode terminal 46 and the negative electrode terminal 47 from the lid body 33 is attached to the positive electrode terminal 46 and the negative electrode terminal 47, respectively (FIGS. 5 and 6A). FIG. 6B). The case 11 is filled with an electrolytic solution. The electrolytic solution is filled through the liquid injection port 38 after the electrode assembly 40 is accommodated in the battery case 31. The electrolytic solution is an electrolytic solution according to the type of secondary battery such as a lithium secondary battery or a nickel hydride secondary battery.

  In a state where the plurality of battery cells 30 are held by the battery holder 23, the lid 33 is on the upper side. The battery module 20 in the present embodiment has an odd number of battery cells 30 arranged in parallel, and each battery cell 30 is connected so that the positive electrode terminal 46 and the negative electrode terminal 47 are adjacent to each other. For this reason, the battery cell 30 provided at one end of the battery cell 30 in the juxtaposed direction and the battery cell 30 provided at the other end of the juxtaposed direction have terminals of the same polarity on the side wall 15 side of the case 11. Are provided respectively. In the case of the battery module 20 shown in FIG. 2, in the battery cells 30 provided at both ends in the juxtaposed direction, the positive terminal 46 is disposed on the side wall 15 side of the case 11, and the negative terminal 47 is the lid member 19 of the case 11. Arranged on each side. The battery cells 30 arranged in parallel are electrically connected by a bus bar 49 (see FIGS. 2 and 3). In the present embodiment, a plurality of battery cells 30 are connected in series.

  Here, the electric current interruption mechanism 50 with which the battery cell 30 is provided is demonstrated. The current interruption mechanism 50 shown in FIG. 6 (A) and FIG. 6 (B) has a negative electrode when the pressure in the battery case 31 is increased by the gas generated from the electrode assembly 40 when the battery cell 30 is overcharged. It is provided to cut off the energization between the terminal 47 and the negative electrode current collector 45. The current interruption mechanism 50 constitutes a part of an energization path that electrically connects the electrode assembly 40 and the negative electrode terminal 47. The current interruption mechanism 50 prevents gas from flowing between the inside of the battery case 31 in which the electrode assembly 40 is accommodated and the outside of the battery case 31. The current interruption mechanism 50 interrupts the energization path between the electrode assembly 40 and the negative electrode terminal 47 when the internal pressure in the battery case 31 exceeds a preset set pressure. The set pressure means the internal pressure in the battery case 31 when the battery cell 30 is in an overcharged (overvoltage) state or when the battery module 20 is in an overheated state (thermal runaway temperature of the active material). The set pressure is set according to conditions such as the capacity of the battery cell 30 and the output voltage.

  The current interruption mechanism 50 is disposed in the battery case 31 and is disposed below the negative electrode terminal 47. The current interruption mechanism 50 includes a flange portion 51 formed integrally with the end portion of the negative electrode terminal 47 on the electrode assembly 40 side. An annular first seal member 52 is interposed between the flange portion 51 and the lid body 33, and the first seal member 52 blocks communication between the inside of the battery case 31 and the outside of the battery case 31. On the electrode assembly 40 side of the outer peripheral portion of the flange portion 51, a rib 53 is formed in an annular shape in the circumferential direction. The rib 53 protrudes toward the electrode assembly 40 side. A disc-shaped contact plate 54 is attached to the rib 53. The contact plate 54 is formed of a conductive material, and is formed in a gentle convex shape so as to approach the electrode assembly 40 side toward the center. Accordingly, a space S1 defined by the flange 51 and the contact plate 54 is formed. An annular second seal member 55 formed of an insulating material is provided on the outer peripheral edge of the contact plate 54 on the electrode assembly 40 side.

  On the electrode assembly 40 side of the second seal member 55, a disk-shaped energization plate 56 made of a conductive material is installed. The outer peripheral portion of the energization plate 56 is connected to the negative electrode current collector 45. The surface (upper surface) of the energization plate 56 on the negative electrode terminal 47 side is flat, and the center portion of the energization plate 56 and the center portion of the contact plate 54 are in contact with each other to form a contact portion 57. Therefore, an energization path that leads to the negative electrode current collector 45, the energization plate 56, the contact portion 57, the contact plate 54, and the negative electrode terminal 47 is formed in the battery cell 30. The surface (lower surface) of the current-carrying plate 56 on the electrode assembly 40 side has a concave shape at the center. For this reason, the plate | board thickness of the center part of the electricity supply board 56 is smaller than the plate | board thickness of the outer peripheral part of the electricity supply board 56. FIG. An annular groove 58 is formed on the lower surface of the central portion of the energization plate 56. The annular groove 58 is an annular groove formed around the center of the energizing plate 56. A contact portion 57 between the contact plate 54 and the energizing plate 56 is located inside the annular groove 58. Since the annular groove 58 is formed in the energizing plate 56, the circular portion inside the annular groove 58 in the energizing plate 56 is broken along the annular groove 58 when a certain external force is applied from below. easy. An annular third seal member 59 formed of an insulating material is provided on the electrode assembly 40 side of the outer peripheral portion of the energization plate 56.

  On the side of the electrode assembly 40 of the third seal member 59, a disc-shaped deformation plate 60 made of a conductive material is installed. The outer peripheral portion of the deformation plate 60 is supported by a support member 61. The support member 61 is formed of a resin material, and holds the contact plate 54, the second seal member 55, the energization plate 56, the third seal member 59, and the deformation plate 60 with respect to the flange portion 51. A metal caulking member 62 is provided on the outer peripheral surface of the support member 61. The caulking member 62 ensures the holding of the contact plate 54, the second seal member 55, the energization plate 56, the third seal member 59, and the deformation plate 60 by the support member 61.

  The deformation plate 60 is formed in a gentle convex shape so as to move away from the energization plate 56 toward the center. Therefore, a space portion S2 defined by the deformable plate 60 and the energizing plate 56 is formed. The deformation plate 60 is formed of a thin metal plate and can be deformed, and has a reversing portion 63 that can be reversed by deformation. The reversing unit 63 momentarily reverses from a convex shape to a concave shape when the internal pressure in the battery cell 30 exceeds the set pressure. An insulating protrusion 64 that protrudes toward the energizing plate 56 is provided at the center of the reversing part 63. In the present embodiment, the shape of the protrusion 64 is a columnar shape, but the shape of the protrusion 64 is not particularly limited. The surface of the deformation plate 60 opposite to the surface on which the protrusions 64 are provided is exposed in a space where the electrolytic solution exists. Installation of the deformation plate 60 isolates the space S2 defined by the deformation plate 60 and the energization plate 56 from the space in which the electrolytic solution in the battery cell 30 exists.

  In this embodiment, when the internal pressure in the battery cell 30 exceeds the set pressure, as shown in FIG. 6B, the reversing portion 63 of the deformation plate 60 instantaneously reverses from a convex shape to a concave shape, and the deformation plate 60 Transforms. The deformation plate 60 generates a sound having a constant volume (hereinafter referred to as “operation sound”) during deformation, and the operation sound of the deformation plate 60 includes a high frequency component having a predetermined frequency or higher. The frequency of the operating sound of the deforming plate 60 can be set mainly depending on the dimensional condition of the deforming plate 60. Specifically, the frequency of the operating sound increases as the size of the deforming plate 60 decreases. The deformation plate 60 satisfies the condition that it can be deformed when it exceeds a preset pressure in advance, and it is easy to distinguish from other sounds (such as the operation sound of the safety valve 37 and the noise outside the battery pack 10). Is preferably set to the shape and dimensions that are generated during deformation. A preferable operation sound of the deformable plate 60 is an audible sound that is instantaneously generated, for example, “click”. The operating sound when the deforming plate 60 is deformed corresponds to the operating sound of the current interrupt mechanism 50.

  When the internal pressure in the battery cell 30 does not exceed the set pressure, the current interruption mechanism 50 maintains the contact between the contact plate 54 and the energizing plate 56 by the contact portion 57 as shown in FIG. When the internal pressure in the battery cell 30 exceeds the set pressure, as shown in FIG. 6 (B), the reversing portion 63 of the deformation plate 60 is momentarily reversed from a convex shape to a concave shape and deformed, and a predetermined frequency or more is reached. An operating sound containing high frequency components is generated. Due to the reversal of the reversing part 63, the protrusion 64 collides with the energizing plate 56 and presses it. The energizing plate 56 is broken along the annular groove 58 to form a circular broken portion 65. The breaking portion 65 is pressed against the contact plate 54 by the protrusion 64, and the electrical contact between the contact plate 54 and the energizing plate 56 is eliminated. By eliminating the contact between the contact plate 54 and the energization plate 56, the energization path between the negative electrode current collector 45 and the negative electrode terminal 47 is physically interrupted. That is, when the current interruption mechanism 50 operates, this energization path is physically interrupted, and the energization in the battery cell 30 is forcibly interrupted.

  By the way, in this embodiment, a sound sensor 70 that detects sound and transmits a sound detection signal is provided for each battery module 20. Specifically, a sound sensor 70 is attached to the inside of the mounting plate 26. The sound sensor 70 uses an electrostatic (condenser) microphone or an electrodynamic microphone. The sound sensor 70 is connected to the monitoring ECU 27, and the detection signal of the sound sensor is output to the monitoring ECU. The sound sensor 70 detects various sounds, but can detect an operation sound when the deformation plate 60 is deformed (when the reversing unit 63 is reversed).

  The monitoring ECU 27 of this embodiment has a function as an operation detection unit that detects the operation of the current interrupt mechanism 50. As shown in FIG. 7, the monitoring ECU 27 includes a high-pass filter circuit unit 71 as high-pass filter means. The high-pass filter circuit unit 71 has an RC circuit, an LC circuit, or an RL circuit. The high-pass filter circuit unit 71 functions to attenuate a frequency component less than a preset set frequency in the sound detection signal output from the sound sensor 70 and output a frequency component greater than the set frequency with little attenuation. Is provided. The monitoring ECU 27 stores a set duration based on the duration of the operating sound when the deformable plate 60 is deformed. Therefore, the monitoring ECU 27 determines whether or not the detection signal output from the high-pass filter circuit unit 71 includes a frequency component equal to or higher than the set frequency, and compares the sound duration with the set duration using the sound sensor 70. The operation of the current interrupt mechanism 50 is detected.

  When the detection signal output from the high-pass filter circuit unit 71 includes a frequency component that is equal to or higher than the set frequency and the duration of the sound matches the set duration, the monitoring ECU 27 confirms that the current cutoff mechanism 50 has been activated. To detect. The monitoring ECU 27 does not detect that the current cutoff mechanism 50 has been activated when the detection signal output from the high-pass filter circuit unit 71 does not include a frequency component equal to or higher than the set frequency. Similarly, when the duration of the sound detected by the sound sensor 70 is different from the set operation time, for example, longer than the set operation time, the monitoring ECU 27 does not detect that the current interrupt mechanism 50 has been operated.

Next, the operation of the battery pack 10 of this embodiment will be described.
When charging each battery module 20 of the battery pack 10, the monitoring ECU 27 monitors the state of the battery module 20 being charged. The control ECU 21 controls the battery module 20 through the monitoring ECU 27 based on the monitoring information regarding the state of the battery module 20 of the monitoring ECU 27. When the monitoring ECU 27 appropriately monitors the battery module 20 and the control ECU 21 performs appropriate charging control, the internal pressure of the battery cell 30 does not exceed the set pressure, and the current interruption mechanism 50 does not operate. On the other hand, when the charge control cannot be appropriately performed for some reason, for example, when a failure occurs in a specific battery cell 30 or when the monitoring function of the monitoring ECU 27 that monitors the battery cell 30 is not normal, the battery cell 30 may have a current greater than normal. In that case, the battery cell 30 is likely to be in an overcharged state. When an abnormality such as an overcharged state occurs in the battery cell 30, gas is generated in the sealed battery case 31. When the gas is generated, the pressure in the battery case 31 rises, and when the gas pressure exceeds the set pressure, the current interrupt mechanism 50 operates.

  When the current interrupting mechanism 50 operates, as shown in FIG. 6B, the reversing portion 63 of the deformable plate 60 momentarily reverses from a convex shape to a concave shape, and includes an operation including a high frequency component of a predetermined frequency or more at the time of reversal. Sound is generated. When the protrusion 64 collides with the current supply plate 56 due to the reversal of the reversal portion 63, the current supply plate 56 is broken along the annular groove 58 to form a breakage portion 65. The fractured portion 65 is pressed against the contact plate 54 by the protrusion 64, and the contact between the contact plate 54 and the energizing plate 56 is eliminated. When the contact between the contact plate 54 and the energization plate 56 is eliminated, the energization path is interrupted. Therefore, even when charging is controlled, the energization path is physically interrupted, and energization in the battery cell 30 is forced. Is interrupted.

  When the current interrupt mechanism 50 is operated, an operation sound including a high frequency component equal to or higher than a predetermined frequency is generated. Therefore, the sound sensor 70 detects the operation sound and outputs a detection signal of the operation sound from the sound sensor 70 to the monitoring ECU 27. . In the high-pass filter circuit unit 71, a frequency component equal to or higher than a preset set frequency is output without being attenuated in the detection signal of the operating sound output from the sound sensor 70. Frequency components less than the set frequency included in the operating sound are attenuated and hardly output. When the sound sensor 70 detects the operation sound of the deformation plate 60, the detection signal after the output of the high-pass filter circuit unit 71 includes a frequency component that is equal to or higher than a preset set frequency, and the operation sound continues. The time matches the set duration. When the detection signal output from the high-pass filter circuit unit 71 includes a frequency component that is equal to or higher than a preset frequency, the monitoring ECU 27 matches the duration of the sound detected by the sound sensor 70 with the preset duration. Then, it is detected that the current interruption mechanism 50 is operated. The detection information of the operation of the current interruption mechanism 50 by the monitoring ECU 27 is transmitted to the control ECU 21, and the control ECU 21 controls the monitoring ECU 27 so as to stop the charging control.

  The sound sensor 70 detects a sound other than the operating sound of the current interrupt mechanism 50 and outputs a detection signal. In the case of a sound detection signal other than the operation sound of the current interrupt mechanism 50, the detection signal after the output of the high-pass filter circuit unit 71 does not include the set frequency or the sound duration does not match the set duration. . The monitoring ECU 27 detects that the current interrupting mechanism 50 is activated when the set frequency is not included in the detection signal output from the high-pass filter circuit unit 71 or the duration of the sound does not match the set duration. do not do. If the monitoring ECU 27 does not detect that the current interrupt mechanism 50 is activated, the control ECU 21 continues to control charging. The sound sensor 70 detects an operating sound of the current interrupt mechanism 50 when the current interrupt mechanism 50 operates not only when the battery pack 10 is charged but also when the battery pack 10 is discharged. Then, the monitoring ECU 27 detects that the current interrupting mechanism 50 is activated by comparing the detection signal after the output of the high-pass filter circuit unit 71 and the duration of the operation sound with the set duration.

According to the battery pack 10 of this embodiment, there exist the following effects.
(1) The sound sensor 70 outputs a detection signal of the detected sound, and the high-pass filter circuit unit 71 outputs a frequency component equal to or higher than a preset set frequency among the detection signals output from the sound sensor 70. When the detection signal after the output of the high-pass filter circuit unit 71 includes a frequency component equal to or higher than the set frequency, and the duration of the sound detected by the sound sensor 70 matches the set duration, the monitoring ECU 27 sets the current interruption mechanism 50. Detect that is activated. That is, if the current interruption mechanism 50 operates, the operation of the current interruption mechanism 50 can be reliably detected. Thereby, it is possible to avoid a re-conduction state in which the disconnection of the energization path after the operation of the current interrupt mechanism 50 is automatically released.

(2) Since the operating noise of the current interruption mechanism 50 includes a frequency component that is equal to or higher than a preset set frequency, even if the battery pack 10 is mounted on the vehicle, various noises generated during the traveling of the vehicle It becomes easy to distinguish from the operating sound of the current interrupt mechanism 50. Therefore, even if the current interrupting mechanism 50 is activated when the vehicle is running, the operation sound of the current interrupting mechanism 50 is detected separately from various noises, and it can be detected that the current interrupting mechanism 50 is activated. The battery pack 10 for mounting on a vehicle is suitable.

(3) The duration of the operation sound of the current interrupt mechanism 50 matches the preset set duration. For this reason, even when the detection signal after the output of the high-pass filter circuit unit 71 includes a frequency component that is equal to or higher than the set frequency, for example, when the duration of the detected sound is longer than the set duration, the monitoring ECU 27 Does not detect that the current interrupt mechanism 50 has been activated. That is, even if the sound includes the same frequency component as the operating sound of the current interrupting mechanism 50, it is not erroneously detected that the current interrupting mechanism 50 is operating.

(4) When the internal pressure of the battery cell 30 reaches a set value or more, the reversing portion 63 of the deformation plate 60 is momentarily reversed to generate an operation sound including a component having a frequency equal to or higher than the set frequency. For this reason, it becomes easy to distinguish from sounds other than the operation sound of the current interruption mechanism 50, and it can detect more reliably that the current interruption mechanism 50 was operated. In particular, the deforming plate 60 is provided with a reversing portion 63 that momentarily reverses when the internal pressure of the battery cell 30 reaches a set value or more, so that an operating sound with a short duration can be set.

(5) The dimension of the deformable plate 60 satisfies the condition that it can be deformed when a preset pressure is exceeded, and is distinguished from other sounds (such as the operating sound of the safety valve 37 and noise outside the battery pack 10). It is possible to set a high-frequency operating sound that is easy.

(6) Since the battery module 20 is accommodated in the case 11, it is possible to easily block sound other than the operation sound of the current interrupt mechanism 50 by the case 11. For this reason, it becomes easier to distinguish from the sound other than the operating sound, and it is possible to more reliably detect that the current interrupting mechanism 50 is operated.

(7) Since the sound sensor 70 and the monitoring ECU 27 are provided for each battery module 20, it is possible to detect that the current interruption mechanism 50 is operated in the battery module 20 unit. For this reason, even if it is detected that the current interruption mechanism 50 in the specific battery module 20 is activated, the charging and discharging control of other battery modules 20 excluding the battery module 20 that detects the operation of the current interruption mechanism 50 is controlled. It is also possible to do this.

  As a modification of the present embodiment, for example, a battery pack 10 shown in FIG. 8 may be used. In the battery pack 10 shown in FIG. 8, the sound sensor 70 is not provided for each battery module 20, but the sound sensor 70 is provided at two locations in the battery case 31. Specifically, the sound sensor 70 is attached to the side wall 15 so as to be positioned between the battery module 20 on the bottom 12 side of the first battery group G1 and the side wall 14. Another sound sensor 70 is attached to the side wall 15 so as to be positioned between the control ECU 21 and the side wall 13. The two sound sensors 70 may be connected to a specific monitoring ECU 27 or may be connected to the control ECU 21. In this modification, it is comprised so that the operation sound of the electric current interruption | blocking mechanism 50 in all the battery cells 30 can be detected with the two sound sensors 70. FIG. When it is detected that the current interrupt mechanism 50 is activated, the control ECU 21 performs control to stop charging or discharging control for all the battery modules 20. In the case of this modification, the number of sound sensors 70 can be reduced, and the manufacturing cost can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.

○ In the above embodiment, when the detection signal after the output of the high-pass filter circuit unit includes a frequency component equal to or higher than the set frequency and the duration of the sound matches the set duration, the monitoring ECU operates the current cutoff mechanism However, this is not the case. For example, it may be detected that the current cut-off mechanism is activated by satisfying the condition that the detection signal output from the high-pass filter circuit unit includes a frequency component equal to or higher than the set frequency. In other words, it may be detected that the current interrupting mechanism is activated even if the duration of the operating sound does not satisfy the condition that matches the set duration.
In the above embodiment, the monitoring ECU as the operation detection means is provided with the high-pass filter circuit unit as the high-pass filter means in the monitoring ECU, but the high-pass filter means is not limited to being provided in the monitoring ECU. For example, the sound sensor and the operation detection unit may be electrically connected, and a high-pass filter circuit may be interposed between the sound sensor and the operation detection unit.
In the above embodiment, the high-pass filter means is a high-pass filter circuit including an RC circuit, an LC circuit, or an RL circuit, but is not limited to a circuit. The high-pass filter means may be a computer and a program, for example. By executing the program, the computer attenuates the frequency components below the preset frequency from the sound detection signal output from the sound sensor, and outputs the frequency components above the preset frequency with little attenuation. It only has to function.
In the above embodiment, the battery pack includes the case. However, for example, the case may be formed of a soundproofing material so as to improve soundproofing properties, or the soundproofing material may be provided on the case. In this case, noise or the like outside the case can be blocked by forming the case with a soundproof material or by providing the case with a soundproof material. For this reason, it is possible to make it difficult to detect sounds other than the operation sound of the current interruption mechanism of the sound sensor, and to make it easier to distinguish between the operation sound of the current interruption mechanism and the sound other than the operation sound of the current interruption mechanism. Can do.
○ In the above embodiment, the protrusion provided on the deformation plate of the current interrupt mechanism breaks the current plate, eliminating the contact portion between the contact plate and the current plate, and eliminating the contact between the contact plate and the current plate. The configuration of the current interruption mechanism is not limited to this. The current interrupting mechanism is not particularly limited as long as the current interrupting mechanism has a member corresponding to a deformed plate that is instantaneously deformed by a pressure equal to or higher than the set pressure in the battery cell.
In the above embodiment, the battery pack including five battery modules is illustrated, but the number of battery modules is not particularly limited. The number of battery modules may be one or more. For example, the number of battery modules may be one. In this case, it is preferable that a case for housing the battery module is provided, and the sound sensor may be provided in the battery module or in the case.

10 battery pack 11 case 20 battery module 21 control ECU
27 Monitoring ECU
30 Battery cell 31 Battery case 37 Safety valve 40 Electrode assembly 46 Positive electrode terminal 47 Negative electrode terminal 50 Current interruption mechanism 54 Contact plate 56 Current supply plate 57 Contact portion 60 Deformation plate 63 Inversion portion 64 Projection body 70 Sound sensor 71 High-pass filter circuit portion G1 1 battery group G2 2nd battery group S1, S2 space part

Claims (5)

A plurality of battery cells;
An energization path provided inside the battery cell;
In the battery module having a current interruption mechanism that is provided in the battery cell and interrupts the energization path when the internal pressure of the battery cell is equal to or higher than a set value.
A sound sensor for detecting sound;
High-pass filter means for attenuating a frequency component less than a preset set frequency among the detection signals output by the sound sensor and outputting a frequency component greater than the set frequency without attenuating;
A battery module comprising: an operation detection unit that detects an operation of the current interrupt mechanism based on a detection signal output from the high-pass filter unit.   2. The battery according to claim 1, wherein the operation detecting means detects the operation of the current interrupting mechanism based on a comparison between a duration of sound detected by the sound sensor and a preset set duration. module. The current interrupting mechanism is instantaneously deformed by an internal pressure equal to or higher than the set value of the battery cell, and includes a deforming plate that interrupts the energization path by deformation,
The battery module according to claim 1, wherein the deformation plate emits an operation sound including a component having a frequency equal to or higher than the set frequency when being deformed.   The battery module according to claim 2, wherein the current interruption mechanism emits an operating sound having a duration that matches the set duration.   A battery pack comprising the battery module according to claim 1 and a case in which the battery module is accommodated.

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